Automatic liquid discharge system for gas storage tanks



A ril 2, 1968 I .1. F. KERN ET AL 3,375,848

AUTOMATIC LIQUID DISCHARGE SYSTEM FOR GAS STORAGE TANKS Filed May 19, 1966 2 Sheets-Sheet l J F. KERN ETAL I 3,375,848

AUTOMAT IC LIQUID DISCHARGE SYSTEM FOR GAS STORAGE TANKS Filed May 19, 1966 2 Sheets-Sheet April 2, 1968 r 48 521 fl E 42 J \7 42 F Y? .54

v 2/ 4 40 A /FIE k 74 62 4 ZZ z--- A 72 v j 58 6o as 58 74' 70 Q I INVENTOR5 ITTOI/YKYS United States Patent C) Joseph F. Kern, Massapequa,

Babylon, William C. Kern, Robinson, Massapequa, Equipment Corporation, of New York Filed May 19, 1966, Ser. No. 551,262 4 Claims. (Cl. 137-195) The present invention relates to a drainage means for I an air dryer system or the like. More particularly it relates to a water dump valve for use in such a system which is capable of rapidly passing accumulated condensed water from an air receiver tank.

It is an object of the present invention to provide a drainage system having valve means whose operation is completely automatic thereby functioning properly to clear the air dryer system of condensed water during periods when the normal drainage line is inoperative.

A further object is to provide a valve structure that rapidly and positively functions to eliminate condensed water without necessitating a shutdown of the system as a whole, thereby to maintain substantially uniform pressure within the system.

An additional object is to provide a valve structure of the automatic type which is not subject to failure, such as a failure frequently caused either by oil, sludge or other foreign materials that tend to accumulate at the working parts in known commercially sold devices.

Other objects and advantages of the present invention will be apparent to one skilled in the art as the following discussion, directed to a single preferred embodiment of the instant invention is developed.

In a broad sense the invention is directed to a drainage system including an air receiver tank adapted for fluid communication with a heat exchange unit and pressurized by a compressor unit in fluid communication therewith. The system further includes a valve located within said tank and automatically operable to dump an abnormal accumulation of condensed water from the air receiver. The valve is in the form of a float guide having a fluid port in its Wall structure and provided with a pair of valve seats. A float valve is disposed within said float guide for movement from one seat to the other in response to said abnormal accumulation. A pressure valve means is located at one of said seats. Said second valve is normally closed by the application of tank pressure on a face of a piston check valve but openable when said tank pressure is isolated from said face, when said float valve moves to said other seat, causing a drop in pressure thereby to rapidly dump said abnormal water accumulation from the tank through said pressure valve.

In the drawings which form a part of the present invention and illustrate a preferred embodiment thereof,

FIG. 1 schematically shows a portion of an air dryer system incorporating the valve structure of the present invention;

FIG. 2 shows in vertical section the dump valve in the closed condition; and

FIG. 3 is a view similar to FIG. 2 showing a second sequence in the operation of the dump valve.

As general background for an understanding of the present invention, the basic cycle of an apparatus as partially shown in FIG. 1 is generally that low pressure fluid, either ambient air or, for example, fluid from an evaporator is drawn into the intake port of a compressor. The pressurized fluid thereafter being discharged from the outlet port and passed through a first heat exchanger or fluid precooler. The pressurized fluid, cooled to approximately ambient temperature, is then passed to a receiver tank for storage, use by the system and subsequent recycling through the compressor. It should be noted that condensate forms in the precooler and this flows with the pres surized fluid into the receiver. Generally, and as shown in FIG. 1, a second refrigerated heat exchanger to further cool the fluid is provided at the discharge of the receiver. This cooling results in an additional formation of condensed water that, as will be brought out, continually drains from the transfer device to the air receiver.

Systems such as the one generally referred to above are normally provided with a primary drainage path for constantly passing this condensed water from the unit but it is not uncommon that such paths fail in operation and water accumulates necessitating stoppage of the system to clear the same. Because of the undesirability of water accumulating within the system, the present invention provides an auxiliary discharge path that is automatically operable upon failure of the primary path for one reason or another.

Referring now to the figures and in particular to FIG. 1, there is a schematic showing of an air compressor modulation and water drain system. In general, the structure comprises an air compressor 16 which is driven by motor 12 and pulley drive means 14. The compressor may be any commercially available type, such as a Quincy compressor, model 308. The compressor is provided with an intake port 16 for low pressure fluid, such as ambient air. The compressor also is provided with an output port (not shown) having suitable fitting means for connection to fluid conduit 18. Conduit 18, in turn, connects the output port to the chamber of air receiver tank 20, thereby to pass pressurized fluid to the chamber.

The air precooler 21, situated between the compressor and air receiver, functions to cool the pressurized fluid to a temperature approximating that of ambient temperature and may be included or excluded from the overall system as choice dictates. Thus, the precooler may be provided in addition to the transfer device 36 or the precooler could be the main exchanger and the main source of condensate, thereby obviating the need of the transfer device. As shown in FIG. 1, the output of the precooler is directly communicated with the chamber in the air receiver but it is also contemplated the output could also enter the receiver through guide 44 at a point below the upper valve seat. In either case, the receiver is desirably insulated from ambient air.

An automatic waterdump valve means, denoted by the numeral 22, is mounted within the receiver tank and in communication with the pressurized chamber. The automatic water dump valve means and its immediately associated structure forms the basis of the present invention and will be dis-cussed in detail as this description is developed. A relief valve 24 is connected to one output of the air receiver by means of conduit 26. In turn, the relief valve is in fluid communication with air chamber 28 through conduit 30. An output of chamber 28 is connected, by means of conduit 32, to an unloader mechanism 34 that is mechanically connected to the intake valve (not shown) of air compressor 10. The latter structure, namely the relief valve 24, air chamber 28 and its bleed valve 44 and their operation in conjunction with air receiver 20 and unloading mechanism 34,- comprise the modulation system; This system likewise does not form a part of the present invention and further discussion is deemed unnecessary. 7

Referring again to the schematic view of FIG. 1, the automatic water dump valve is shown to be in fluid connection with a refrigerated heat exchanger 36. It is within the heat exchanger that the pressurized fluid. is substantially cooled, causing condensed water to form the condensation drains to the air receiver 20 by means of conduit 38. It is the condensation which must be eliminated from the system and the present invention is directed to this end.

The present invention may be clearly understood by reference to FIGS. 2 and 3 which are specifically directed to the dump valve mechanism 22. Thus, from the figures, the operation of the dump valve mechanism is sequentially shown as is its orientation within the air receiver 20 and in conjunction with heat exchanger 36, fluid conduit 38 and equalizing line 40 that provides a pressure communication from the receiver to the lower portion of the dump valve or the pressure responsive valve, during normal operation.

As previously noted, the automatic dump valve is an auxiliary unit which functions when the normal drainage path for the condensed water fails in operation. The normal path comprises a part of the air compressor modulation system as defined above. Specifically, the drainage path is from the air receiver 20 and through conduit 26, relief valve 24, air chamber 28 and the drain 42. Therefore, the condensed water that drains to the air receiver from the heat exchanger 36 flows from the former through the path described to the atmosphere or a collecting device. Over and above inadvertant closure of valve 44, it may be stated that failure of the normal drainage path occurs during periods when the pressure in the air receiver falls below a sufiicient mininum to overcome the resilient pressure bias on the relief valve thereby to maintain the latter in a closed position.

In the event of malfunction or failure of the compressor modulating system, thereby causing condensed Water to collect within the air receiver tank, the water accumulation will automatically be discharged through the water dump valve, now to be fully discussed.

The valve is mounted within the air receiver 20 and is partially defined by an elongated cylinder 44 arranged in vertical position and which extends through walls 42 of the receiver. The cylinder carries a plurality of fluid passages 46 along its walls so that the interior of the cylinder is in communication with the receiver chamber and therefore subject to the same pressure. At the upper and lower extremities of the cylinder are a pair of valve seats 48 and 50, supported respectively by cap members 52 and 54 which are suitably connected to the cylinder. The valve seats 48 and 50 may be of any general construction, being shown as cylindrical members supported by the caps. The seats are designated as an upper and lower seat, respectively.

Within the cylindrical member 44 and responsive to a rise in the condensate level within the air receiver tank is a float valve 56. As may be apparent, the float valve is subject to the chamber pressure thereby, under normal operating conditions when little or no condensate is present, sealing the lower valve seat 50.

The float valve may be of any suitable buoyant material that will respond to changes in liquid level, such as a foamed plastic material. In FIG. 2, the valve is positioned at the lower seat and during normal operation will be retained at the lower seat by the pressure within the air receiver. Therefore, during such normal operation the condensate discharge path from the air receiver through the piston valve structure, generally denoted by the number 58, is closed.

The piston valve structure is in the form of a cylinder 60 which is suitably mounted on the lower valve seat 50. Within the cylinder is a piston seat 62 in the form of an annular ring which effectively divides the cylinder chamber into an upper chamber 64 and a lower chamber 66.

A piston member 68 capable of reciprocating movement is slidably received in the lower chamber 66 and carries on its surface a pair of O-rings 70 to provide a tight fluid seal between the cylinder wall and the piston. Also within the lower chamber are a plurality of ports 72 for dumping water from the air receiver. Conveniently placed around the ports is a water shield 74.

When the system is operating normally, i.e., the air receiver tank 20 is being maintained at a relatively constant pressure of, for example, p.s.i.g., the modulation system is functioning and condensate is continually passing from the air receiver through the normal path described above. This operation is shown in FIG. 2. Thus, the air receiver is supplying the constant discharge pressure to heat exchanger 36 through upper valve port 48 and line 38, with the exchanger also being maintained at 150 p.s.i.g. By means of equalizing line 40, the pressure of receiver 20 acts upon the lower face of piston 68. Therefore, piston 68 is pressure biased upwardly to close valve 58. Float valve 56 is also subjected to air receiver pressure so as to rest on and seal valve seat 50. Under these conditions, no air or condensed liquid will be discharged from the air receiver by the dump valve through outlet openings 72. The condensed water discharge path to atmosphere will be through the modulation system, as discussed.

Assume that the modulation system fails and the level of condensed water within the air receiver begins to rise. Under these circumstances, the float will react to the change in liquid level within the air receiver, float on the liquid, and move from the lower valve seat 50. Until such time as the float member 56 reaches and seals the upper valve seat 48, the receiver pressure is communicated to the lower cylinder chamber 66 to maintain piston member 68 in the position of FIG. 2. When the water within the air receiver tank has risen sufficiently to cause the float to seal the upper valve seat 48 the pressure within conduits 38 and 40, due to system demands, drops rapidly whereby the piston member, due to high pressure within the receiver, falls to the position as in FIG. 3. Since the drop in pressure within line 40 is rapid the piston drops quickly and the receiver pressure causes a rapid dump ing of the liquid condensate accumulation through outlet 72. Actually, the liquid is dumped at a rate which is faster than the reaction time of the float to the falling water line.

When the water accumulation has been discharged from the air receiver tank the float again seats against the lower valve 50. The pressure within the receiver returns to the predetermined pressure of approximately 150 p.s.i.g. due to the constant compressor operation, again pressurizing the system and the equalizing line 40. Thereby, piston member 68 returns to valve closing position, closing the fluid path from air receiver 20 to the atmosphere through ports 72.

While the present invention has been discussed in relation to a preferred embodiment of the present invention which carries out the objects and provides the advantages as aforementioned, it should be apparent that certain modifications of the present invention are within the scope of the invention and that the invention is not otherwise to be limited than by the breadth of the appendend claims.

Having described the invention what is claimed is:

1. An automatic drainage means comprising an air receiver tank provided with a chamber adapted to be connected to the output of an air compressor whereby said chamber is maintained at an elevated pressure, an elongated float guide member mounted within said chamber and having at least one fluid port formed in the wall portion thereof providing direct fluid communication with said chamber, a first valve seat formed adjacent one end of the elongated float guide adapted for fluid communication with a heat transfer device thereby to pass gas to said transfer device and receive condensate from said device, a second valve seat formed adjacent the other end of said float guide, a float valve received within said float guide normally positioned at and in sealing relation to said second valve seat, and a pressure controlled valve means mounted in fluid communication with said second valve seat to control drainage of said condensate therethrough, a pressure line connecting said first valve seat to said pressure controlled valve means to maintain said pressure valve means in a closed condition when said float valve is removed from said first valve seat, said pressure valve opening when said float valve moves to said first valve seat under influence of the condensate level whereby condensate accumulations in said air receiver tank are dumped from said chamber.

2. An automatic drainage mechanism for draining liquid from a system containing both gas and a liquid contaminate comprising a receiver tank having a chamber adapted for communication with a source of the gas and a liquid contaminate so that the liquid can flow therein, an elongated float guide mounted in said receiver tank extending transversely of said chamber in a vertical direction and having an opening providing direct fluid communication with the chamber, first valve seat at the upper end of said guide providing a first outlet through which gas can escape from the chamber and liquid can drain downwardly into the chamber, a second valve seat at the lower end of said guide providing a second outlet through which liquid can drain from the system, a pressure controlled valve assembly mounted adjacent second valve seat and connecting with said second outlet to control drainage of the liquid therethrough and comprising a third valve seat connecting with said second outlet and providing a drainage path for said liquid, a pressure operated valve beneath said third valve seat and shiftable between closed position in engagement therewith and opened position spaced therefrom, a float valve disposed within said guide and capable of floating on said liquid thereby to shift from a normal position closing said second valve seat when no liquid is present in said chamber to a position closing said first valve seat when suflicient liquid accumulates in the chamber, and a pressure line connecting at one end with the first outlet and at. the other end with the lower side of the pressure operated valve whereby the pressure operated valve is closed by gas pressure when the float valve closes said second valve seat and is opened when the gas pressure is shut oil by the closing of the first valve seat by the float valve.

3. The automatic drainage system of claim 2 wherein said float valve is defined by a foamed plastic material that responds to condensed liquid accumulation levels in said air receiver tank.

4. The automatic drainage system of claim 2 wherein said float valve prevents liquid contaminate from reentering the system when said float closes said first valve seat.

References Cited UNITED STATES PATENTS 2,949,925 8/1960 Everett 137195 ALAN COHAN, Primary Examiner. 

1. AN AUTOMATIC DRAINAGE MEANS COMPRISING AN AIR RECEIVER TANK PROVIDED WITH A CHAMBER ADAPTED TO BE CONNECTED TO THE OUTPUT OF AN AIR COMPRESSOR WHEREBY SAID CHAMBER IS MAINTAINED AT AN ELEVATED PRESSURE, AN ELONGATED FLOAT GUIDE MEMBER MOUNTED WITHIN SAID CHAMBER AND HAVING AT LEAST ONE FLUID PORT FORMED IN THE WALL PORTION THEREOF PROVIDING DIRECT FLUID COMMUNICATION WITH SAID CHAMBER, A FIRST VALVE SEAT FORMED ADJACENT ONE END OF THE ELONGATED FLOAT GUIDE ADAPTED FOR FLUID COMMUNICATION WITH A HEAT TRANSFER DEVICE THEREBY TO PASS GAS TO SAID TRANSFER DEVICE AND RECEIVE CONDENSATE FROM SAID DEVICE, A SECOND VALVE SEAT FORMED ADJACENT THE OTHER END OF SAID FLOAT GUIDE, A FLOAT VALVE RECEIVED WITHIN 